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Sun S, Zhou J, Liu P. Liquid-liquid phase separation of microtubule-binding proteins in the regulation of spindle assembly. Cell Prolif 2024:e13649. [PMID: 38736355 DOI: 10.1111/cpr.13649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 03/19/2024] [Accepted: 04/15/2024] [Indexed: 05/14/2024] Open
Abstract
Cell division is a highly regulated process essential for the accurate segregation of chromosomes. Central to this process is the assembly of a bipolar mitotic spindle, a highly dynamic microtubule (MT)-based structure responsible for chromosome movement. The nucleation and dynamics of MTs are intricately regulated by MT-binding proteins. Over the recent years, various MT-binding proteins have been reported to undergo liquid-liquid phase separation, forming either single- or multi-component condensates on MTs. Herein, we provide a comprehensive summary of the phase separation characteristics of these proteins. We underscore their critical roles in MT nucleation, spindle assembly and kinetochore-MT attachment during the cell division process. Furthermore, we discuss the current challenges and various remaining unsolved problems, highlights the ongoing research efforts aimed at a deeper understanding of the role of the phase separation process during spindle assembly and orientation. Our review aims to contribute to the collective knowledge in this area and stimulate further investigations that will enhance our comprehension of the intricate mechanisms governing cell division.
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Affiliation(s)
- Shuang Sun
- Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Institute of Biomedical Sciences, College of Life Sciences, Shandong Normal University, Jinan, China
| | - Jun Zhou
- Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Institute of Biomedical Sciences, College of Life Sciences, Shandong Normal University, Jinan, China
- State Key Laboratory of Medicinal Chemical Biology, Haihe Laboratory of Cell Ecosystem, College of Life Sciences, Nankai University, Tianjin, China
| | - Peiwei Liu
- Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Institute of Biomedical Sciences, College of Life Sciences, Shandong Normal University, Jinan, China
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2
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Lakshmi RB, Nayak P, Raz L, Sarkar A, Saroha A, Kumari P, Nair VM, Kombarakkaran DP, Sajana S, M G S, Agasti SS, Paul R, Ben-David U, Manna TK. CKAP5 stabilizes CENP-E at kinetochores by regulating microtubule-chromosome attachments. EMBO Rep 2024; 25:1909-1935. [PMID: 38424231 PMCID: PMC11014917 DOI: 10.1038/s44319-024-00106-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2023] [Revised: 02/02/2024] [Accepted: 02/12/2024] [Indexed: 03/02/2024] Open
Abstract
Stabilization of microtubule plus end-directed kinesin CENP-E at the metaphase kinetochores is important for chromosome alignment, but its mechanism remains unclear. Here, we show that CKAP5, a conserved microtubule plus tip protein, regulates CENP-E at kinetochores in human cells. Depletion of CKAP5 impairs CENP-E localization at kinetochores at the metaphase plate and results in increased kinetochore-microtubule stability and attachment errors. Erroneous attachments are also supported by computational modeling. Analysis of CKAP5 knockout cancer cells of multiple tissue origins shows that CKAP5 is preferentially essential in aneuploid, chromosomally unstable cells, and the sensitivity to CKAP5 depletion is correlated to that of CENP-E depletion. CKAP5 depletion leads to reduction in CENP-E-BubR1 interaction and the interaction is rescued by TOG4-TOG5 domain of CKAP5. The same domain can rescue CKAP5 depletion-induced CENP-E removal from the kinetochores. Interestingly, CKAP5 depletion facilitates recruitment of PP1 to the kinetochores and furthermore, a PP1 target site-specific CENP-E phospho-mimicking mutant gets stabilized at kinetochores in the CKAP5-depleted cells. Together, the results support a model in which CKAP5 controls mitotic chromosome attachment errors by stabilizing CENP-E at kinetochores and by regulating stability of the kinetochore-attached microtubules.
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Affiliation(s)
- R Bhagya Lakshmi
- School of Biology, Indian Institute of Science Education and Research, Thiruvananthapuram, Vithura, Thiruvananthapuram, Kerala, 695551, India
| | - Pinaki Nayak
- School of Mathematical and Computational Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata, 700032, India
| | - Linoy Raz
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Apurba Sarkar
- School of Mathematical and Computational Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata, 700032, India
| | - Akshay Saroha
- New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru, Karnataka, 560064, India
| | - Pratibha Kumari
- New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru, Karnataka, 560064, India
| | - Vishnu M Nair
- School of Biology, Indian Institute of Science Education and Research, Thiruvananthapuram, Vithura, Thiruvananthapuram, Kerala, 695551, India
| | - Delvin P Kombarakkaran
- School of Biology, Indian Institute of Science Education and Research, Thiruvananthapuram, Vithura, Thiruvananthapuram, Kerala, 695551, India
| | - S Sajana
- School of Biology, Indian Institute of Science Education and Research, Thiruvananthapuram, Vithura, Thiruvananthapuram, Kerala, 695551, India
| | - Sanusha M G
- School of Biology, Indian Institute of Science Education and Research, Thiruvananthapuram, Vithura, Thiruvananthapuram, Kerala, 695551, India
| | - Sarit S Agasti
- New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru, Karnataka, 560064, India
| | - Raja Paul
- School of Mathematical and Computational Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata, 700032, India
| | - Uri Ben-David
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Tapas K Manna
- School of Biology, Indian Institute of Science Education and Research, Thiruvananthapuram, Vithura, Thiruvananthapuram, Kerala, 695551, India.
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3
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Ryu J, Lee SH, Kim S, Jeong JW, Kim KS, Nam S, Kim JE. Urban dust particles disrupt mitotic progression by dysregulating Aurora kinase B-related functions. JOURNAL OF HAZARDOUS MATERIALS 2023; 459:132238. [PMID: 37586242 DOI: 10.1016/j.jhazmat.2023.132238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 08/02/2023] [Accepted: 08/04/2023] [Indexed: 08/18/2023]
Abstract
Particulate matter (PM), a major component of outdoor air pollution, damages DNA and increases the risk of cancer. Although the harmful effects of PM at the genomic level are known, the detailed mechanism by which PM affects chromosomal stability remains unclear. In this study, we investigated the novel effects of PM on mitotic progression and identified the underlying mechanisms. Gene set enrichment analysis of lung cancer patients residing in countries with high PM concentrations revealed the downregulation of genes associated with mitosis and mitotic structures. We also showed that exposure of lung cancer cells in vitro to urban dust particles (UDPs) inhibits cell proliferation through a prolonged M phase. The mitotic spindles in UDP-treated cells were hyperstabilized, and the number of centrioles increased. The rate of ingression of the cleavage furrow and actin clearance from the polar cortex was reduced significantly. The defects in mitotic progression were attributed to inactivation of Aurora B at kinetochore during early mitosis, and spindle midzone and midbody during late mitosis. While previous studies demonstrated possible links between PM and mitosis, they did not specifically identify the dysregulation of spatiotemporal dynamics of mitotic proteins and structures (e.g., microtubules, centrosomes, cleavage furrow, and equatorial and polar cortex), which results in the accumulation of chromosomal instability, ultimately contributing to carcinogenicity. The data highlight the novel scientific problem of PM-induced mitotic disruption. Additionally, we introduce a practical visual method for assessing the genotoxic outcomes of airborne pollutants, which has implications for future environmental and public health research.
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Affiliation(s)
- Jaewook Ryu
- Department of Biomedical Science, Graduate School, Kyung Hee University, Seoul 02447, the Republic of Korea; Department of Pharmacology, College of Medicine, Kyung Hee University, Seoul 02447, the Republic of Korea
| | - Seung Hyeun Lee
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, College of Medicine, Kyung Hee University, Seoul 02447, the Republic of Korea
| | - Sungyeon Kim
- Department of Genome Medicine and Science, AI Convergence Center for Medical Science, Gachon Institute of Genome Medicine and Science, Gachon University Gil Medical Center, Gachon University College of Medicine, Incheon 21565, the Republic of Korea
| | - Joo-Won Jeong
- Department of Biomedical Science, Graduate School, Kyung Hee University, Seoul 02447, the Republic of Korea; Department of Anatomy and Neurobiology, College of Medicine, Kyung Hee University, Seoul 02447, the Republic of Korea
| | - Kyung Sook Kim
- Department of Biomedical Engineering, College of Medicine, Kyung Hee University, Seoul 02447, the Republic of Korea
| | - Seungyoon Nam
- Department of Genome Medicine and Science, AI Convergence Center for Medical Science, Gachon Institute of Genome Medicine and Science, Gachon University Gil Medical Center, Gachon University College of Medicine, Incheon 21565, the Republic of Korea; Department of Health Sciences and Technology, Gachon Advanced Institute for Health Sciences and Technology (GAIHST), Gachon University, Incheon 21999, the Republic of Korea
| | - Ja-Eun Kim
- Department of Biomedical Science, Graduate School, Kyung Hee University, Seoul 02447, the Republic of Korea; Department of Pharmacology, College of Medicine, Kyung Hee University, Seoul 02447, the Republic of Korea; Department of Precision Medicine, Graduate School, Kyung Hee University, Seoul 02447, the Republic of Korea.
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4
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Normandin K, Coulombe-Huntington J, St-Denis C, Bernard A, Bourouh M, Bertomeu T, Tyers M, Archambault V. Genetic enhancers of partial PLK1 inhibition reveal hypersensitivity to kinetochore perturbations. PLoS Genet 2023; 19:e1010903. [PMID: 37639469 PMCID: PMC10491399 DOI: 10.1371/journal.pgen.1010903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 09/08/2023] [Accepted: 08/06/2023] [Indexed: 08/31/2023] Open
Abstract
Polo-like kinase 1 (PLK1) is a serine/threonine kinase required for mitosis and cytokinesis. As cancer cells are often hypersensitive to partial PLK1 inactivation, chemical inhibitors of PLK1 have been developed and tested in clinical trials. However, these small molecule inhibitors alone are not completely effective. PLK1 promotes numerous molecular and cellular events in the cell division cycle and it is unclear which of these events most crucially depend on PLK1 activity. We used a CRISPR-based genome-wide screening strategy to identify genes whose inactivation enhances cell proliferation defects upon partial chemical inhibition of PLK1. Genes identified encode proteins that are functionally linked to PLK1 in multiple ways, most notably factors that promote centromere and kinetochore function. Loss of the kinesin KIF18A or the outer kinetochore protein SKA1 in PLK1-compromised cells resulted in mitotic defects, activation of the spindle assembly checkpoint and nuclear reassembly defects. We also show that PLK1-dependent CENP-A loading at centromeres is extremely sensitive to partial PLK1 inhibition. Our results suggest that partial inhibition of PLK1 compromises the integrity and function of the centromere/kinetochore complex, rendering cells hypersensitive to different kinetochore perturbations. We propose that KIF18A is a promising target for combinatorial therapies with PLK1 inhibitors.
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Affiliation(s)
- Karine Normandin
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Canada
| | | | - Corinne St-Denis
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Canada
| | - Alexandre Bernard
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Canada
| | - Mohammed Bourouh
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Canada
| | - Thierry Bertomeu
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Canada
| | - Mike Tyers
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Canada
- Département de médecine, Université de Montréal, Montréal, Canada
| | - Vincent Archambault
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Canada
- Département de biochimie et médecine moléculaire, Université de Montréal, Montréal, Canada
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5
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Influence of Ranunculus acris Flower Extract on Allium cepa Root Meristem. INTERNATIONAL JOURNAL OF PLANT BIOLOGY 2023. [DOI: 10.3390/ijpb14010008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The plant Ranunculus acris (L.) is widespread. It is used in folk medicine. The use of herbal medicines can have adverse effects on humans and requires studies of herbal raw materials for genotoxicity. The goals of the study were to examine the toxic and genotoxic effects of aqueous solutions of R. acris flowers at concentrations of 0.625%, 1.25%, 2.5%, 5% and 10% using the Allium test and to determine the numbers of flavonoids and polyphenols and the antioxidant activity of the extracts. It has been shown that aqueous solutions of buttercup flower extract have a depressing effect on mitosis in the cells of the root meristem of Allium cepa (L.) and cause chromosomal abnormalities (chromosomal stickiness, chromosome lagging, nuclear buds and bridges in anaphase).
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6
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Li Q, Ma Y, Chang F, Xu Y, Deng J, Duan J, Jiang W, He Q, Xu L, Zhong L, Shao G, Li L. The deubiquitinating enzyme complex BRISC regulates Aurora B activation via lysine-63-linked ubiquitination in mitosis. Commun Biol 2022; 5:1335. [PMID: 36473924 PMCID: PMC9726926 DOI: 10.1038/s42003-022-04299-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 11/24/2022] [Indexed: 12/12/2022] Open
Abstract
Faithful chromosome segregation requires bi-oriented kinetochore-microtubule attachment on the metaphase spindle. Aurora B kinase, the catalytic core of the chromosome passage complex (CPC), plays a crucial role in this process. Aurora B activation has widely been investigated in the context of protein phosphorylation. Here, we report that Aurora B is ubiquitinated in mitosis through lysine-63 ubiquitin chains (K63-Ub), which is required for its activation. Mutation of Aurora B at its primary K63 ubiquitin site inhibits its activation, reduces its kinase activity, and disrupts the association of Aurora B with other components of CPC, leading to severe mitotic defects and cell apoptosis. Moreover, we identify that BRCC36 isopeptidase complex (BRISC) is the K63-specific deubiquitinating enzyme for Aurora B. BRISC deficiency augments the accumulation of Aurora B K63-Ubs, leading to Aurora B hyperactivation and erroneous chromosome-microtubule attachments. These findings define the role of K63-linked ubiquitination in regulating Aurora B activation and provide a potential site for Aurora B-targeting drug design.
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Affiliation(s)
- Qin Li
- grid.11135.370000 0001 2256 9319Department of Cell Biology, School of Basic Medical Sciences, Peking University Health Science Center, 100191 Beijing, China
| | - Yanfang Ma
- grid.11135.370000 0001 2256 9319Department of Cell Biology, School of Basic Medical Sciences, Peking University Health Science Center, 100191 Beijing, China
| | - Fen Chang
- grid.11135.370000 0001 2256 9319Department of Cell Biology, School of Basic Medical Sciences, Peking University Health Science Center, 100191 Beijing, China
| | - Yongjie Xu
- grid.11135.370000 0001 2256 9319Department of Cell Biology, School of Basic Medical Sciences, Peking University Health Science Center, 100191 Beijing, China
| | - Jingcheng Deng
- grid.11135.370000 0001 2256 9319Department of Cell Biology, School of Basic Medical Sciences, Peking University Health Science Center, 100191 Beijing, China
| | - Junyi Duan
- grid.11135.370000 0001 2256 9319Department of Cell Biology, School of Basic Medical Sciences, Peking University Health Science Center, 100191 Beijing, China
| | - Wei Jiang
- grid.11135.370000 0001 2256 9319Department of Biochemistry and Biophysics, School of Basic Medical Sciences, Peking University Health Science Center, 100191 Beijing, China
| | - Qihua He
- grid.11135.370000 0001 2256 9319Center of Medical and Health Analysis, Peking University Health Science Center, 100191 Beijing, China
| | - Luzheng Xu
- grid.11135.370000 0001 2256 9319Center of Medical and Health Analysis, Peking University Health Science Center, 100191 Beijing, China
| | - Lijun Zhong
- grid.11135.370000 0001 2256 9319Center of Medical and Health Analysis, Peking University Health Science Center, 100191 Beijing, China
| | - Genze Shao
- grid.11135.370000 0001 2256 9319Department of Cell Biology, School of Basic Medical Sciences, Peking University Health Science Center, 100191 Beijing, China
| | - Li Li
- grid.11135.370000 0001 2256 9319Department of Cell Biology, School of Basic Medical Sciences, Peking University Health Science Center, 100191 Beijing, China
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7
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Brusini L, Dos Santos Pacheco N, Tromer EC, Soldati-Favre D, Brochet M. Composition and organization of kinetochores show plasticity in apicomplexan chromosome segregation. J Cell Biol 2022; 221:213421. [PMID: 36006241 PMCID: PMC9418836 DOI: 10.1083/jcb.202111084] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 05/31/2022] [Accepted: 07/15/2022] [Indexed: 01/01/2023] Open
Abstract
Kinetochores are multiprotein assemblies directing mitotic spindle attachment and chromosome segregation. In apicomplexan parasites, most known kinetochore components and associated regulators are apparently missing, suggesting a minimal structure with limited control over chromosome segregation. In this study, we use interactomics combined with deep homology searches to identify 13 previously unknown components of kinetochores in Apicomplexa. Apicomplexan kinetochores are highly divergent in sequence and composition from animal and fungal models. The nanoscale organization includes at least four discrete compartments, each displaying different biochemical interactions, subkinetochore localizations and evolutionary rates across the phylum. We reveal alignment of kinetochores at the metaphase plate in both Plasmodium berghei and Toxoplasma gondii, suggestive of a conserved "hold signal" that prevents precocious entry into anaphase. Finally, we show unexpected plasticity in kinetochore composition and segregation between apicomplexan lifecycle stages, suggestive of diverse requirements to maintain fidelity of chromosome segregation across parasite modes of division.
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Affiliation(s)
- Lorenzo Brusini
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland,Correspondence to Lorenzo Brusini:
| | - Nicolas Dos Santos Pacheco
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Eelco C. Tromer
- Cell Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute, Faculty of Science and Engineering, University of Groningen, Groningen, Netherlands
| | - Dominique Soldati-Favre
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Mathieu Brochet
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland,Mathieu Brochet:
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8
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Vukušić K, Tolić IM. Polar Chromosomes—Challenges of a Risky Path. Cells 2022; 11:cells11091531. [PMID: 35563837 PMCID: PMC9101661 DOI: 10.3390/cells11091531] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 04/28/2022] [Accepted: 04/30/2022] [Indexed: 12/29/2022] Open
Abstract
The process of chromosome congression and alignment is at the core of mitotic fidelity. In this review, we discuss distinct spatial routes that the chromosomes take to align during prometaphase, which are characterized by distinct biomolecular requirements. Peripheral polar chromosomes are an intriguing case as their alignment depends on the activity of kinetochore motors, polar ejection forces, and a transition from lateral to end-on attachments to microtubules, all of which can result in the delayed alignment of these chromosomes. Due to their undesirable position close to and often behind the spindle pole, these chromosomes may be particularly prone to the formation of erroneous kinetochore-microtubule interactions, such as merotelic attachments. To prevent such errors, the cell employs intricate mechanisms to preposition the spindle poles with respect to chromosomes, ensure the formation of end-on attachments in restricted spindle regions, repair faulty attachments by error correction mechanisms, and delay segregation by the spindle assembly checkpoint. Despite this protective machinery, there are several ways in which polar chromosomes can fail in alignment, mis-segregate, and lead to aneuploidy. In agreement with this, polar chromosomes are present in certain tumors and may even be involved in the process of tumorigenesis.
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9
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Sarangapani KK, Koch LB, Nelson CR, Asbury CL, Biggins S. Kinetochore-bound Mps1 regulates kinetochore-microtubule attachments via Ndc80 phosphorylation. J Cell Biol 2021; 220:e202106130. [PMID: 34647959 PMCID: PMC8641409 DOI: 10.1083/jcb.202106130] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 08/03/2021] [Accepted: 09/09/2021] [Indexed: 12/22/2022] Open
Abstract
Dividing cells detect and correct erroneous kinetochore-microtubule attachments during mitosis, thereby avoiding chromosome missegregation. The Aurora B kinase phosphorylates microtubule-binding elements specifically at incorrectly attached kinetochores, promoting their release and providing another chance for proper attachments to form. However, growing evidence suggests that the Mps1 kinase is also required for error correction. Here we directly examine how Mps1 activity affects kinetochore-microtubule attachments using a reconstitution-based approach that allows us to separate its effects from Aurora B activity. When endogenous Mps1 that copurifies with kinetochores is activated in vitro, it weakens their attachments to microtubules via phosphorylation of Ndc80, a major microtubule-binding protein. This phosphorylation contributes to error correction because phospho-deficient Ndc80 mutants exhibit genetic interactions and segregation defects when combined with mutants in other error correction pathways. In addition, Mps1 phosphorylation of Ndc80 is stimulated on kinetochores lacking tension. These data suggest that Mps1 provides an additional mechanism for correcting erroneous kinetochore-microtubule attachments, complementing the well-known activity of Aurora B.
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Affiliation(s)
| | - Lori B. Koch
- Howard Hughes Medical Institute, Chevy Chase, MD
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA
- Molecular and Cellular Biology Program, University of Washington, Seattle, WA
| | - Christian R. Nelson
- Howard Hughes Medical Institute, Chevy Chase, MD
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA
| | - Charles L. Asbury
- Department of Physiology & Biophysics, University of Washington, Seattle, WA
| | - Sue Biggins
- Howard Hughes Medical Institute, Chevy Chase, MD
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA
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10
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Song X, Conti D, Shrestha RL, Braun D, Draviam VM. Counteraction between Astrin-PP1 and Cyclin-B-CDK1 pathways protects chromosome-microtubule attachments independent of biorientation. Nat Commun 2021; 12:7010. [PMID: 34853300 PMCID: PMC8636589 DOI: 10.1038/s41467-021-27131-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 11/02/2021] [Indexed: 02/08/2023] Open
Abstract
Defects in chromosome-microtubule attachment can cause chromosomal instability (CIN), frequently associated with infertility and aggressive cancers. Chromosome-microtubule attachment is mediated by a large macromolecular structure, the kinetochore. Sister kinetochores of each chromosome are pulled by microtubules from opposing spindle-poles, a state called biorientation which prevents chromosome missegregation. Kinetochore-microtubule attachments that lack the opposing-pull are detached by Aurora-B/Ipl1. It is unclear how mono-oriented attachments that precede biorientation are spared despite the lack of opposing-pull. Using an RNAi-screen, we uncover a unique role for the Astrin-SKAP complex in protecting mono-oriented attachments. We provide evidence of domains in the microtubule-end associated protein that sense changes specific to end-on kinetochore-microtubule attachments and assemble an outer-kinetochore crescent to stabilise attachments. We find that Astrin-PP1 and Cyclin-B-CDK1 pathways counteract each other to preserve mono-oriented attachments. Thus, CIN prevention pathways are not only surveying attachment defects but also actively recognising and stabilising mature attachments independent of biorientation. Chromosome instability frequently occurs due to issues with chromosome-microtubule attachments. Here the authors show that the Astrin-PP1 and Cyclin-B-CDK1 pathways counteract each other to protect chromosome-microtubule attachments independent of biorientation.
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Affiliation(s)
- Xinhong Song
- School of Biological and Chemical Sciences, Queen Mary, University of London, London, E1 4NS, UK
| | - Duccio Conti
- School of Biological and Chemical Sciences, Queen Mary, University of London, London, E1 4NS, UK.,Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Straße 11, 44227, Dortmund, Germany
| | - Roshan L Shrestha
- Department of Genetics, University of Cambridge, Cambridge, CB2 3EH, UK.,Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Dominique Braun
- Department of Genetics, University of Cambridge, Cambridge, CB2 3EH, UK
| | - Viji M Draviam
- School of Biological and Chemical Sciences, Queen Mary, University of London, London, E1 4NS, UK. .,Department of Genetics, University of Cambridge, Cambridge, CB2 3EH, UK.
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11
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Transcript levels of spindle and kinetochore-associated complex 1/3 as prognostic biomarkers correlated with immune infiltrates in hepatocellular carcinoma. Sci Rep 2021; 11:11165. [PMID: 34045512 PMCID: PMC8160131 DOI: 10.1038/s41598-021-89628-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 04/28/2021] [Indexed: 12/31/2022] Open
Abstract
The spindle and kinetochore-associated protein complex (Ska) is an essential component in chromosome segregation. It comprises three proteins (Ska1, Ska2, and Ska3) with theorized roles in chromosomal instability and tumor development, and its overexpression has been widely reported in a variety of tumors. However, the prognostic significance and immune infiltration of Ska proteins in hepatocellular carcinoma (HCC) are not completely understood. The bioinformatics tools Oncomine, UALCAN, gene expression profiling interactive analysis 2 (GEPIA2), cBioPortal, GeneMANIA, Metascape, and TIMER were used to analyze differential expression, prognostic value, genetic alteration, and immune cell infiltration of the Ska protein complex in HCC patients. We found that the mRNA expression of the Ska complex was markedly upregulated in HCC. High expression of the Ska complex is closely correlated with tumor stage, patient race, tumor grade, and TP53 mutation status. In addition, high expression of the Ska complex was significantly correlated with poor disease-free survival, while the high expression levels of Ska1 and Ska3 were associated with shorter overall survival. The biological functions of the Ska complex in HCC primarily involve the amplification of signals from kinetochores, the mitotic spindle, and (via a MAD2 invasive signal) unattached kinetochores. Furthermore, the expression of the complex was positively correlated with tumor-infiltrating cells. These results may provide new insights into the development of immunotherapeutic targets and prognostic biomarkers for HCC.
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12
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Ludzia P, Lowe ED, Marcianò G, Mohammed S, Redfield C, Akiyoshi B. Structural characterization of KKT4, an unconventional microtubule-binding kinetochore protein. Structure 2021; 29:1014-1028.e8. [PMID: 33915106 PMCID: PMC8443799 DOI: 10.1016/j.str.2021.04.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 02/17/2021] [Accepted: 04/08/2021] [Indexed: 01/01/2023]
Abstract
The kinetochore is the macromolecular machinery that drives chromosome segregation by interacting with spindle microtubules. Kinetoplastids (such as Trypanosoma brucei), a group of evolutionarily divergent eukaryotes, have a unique set of kinetochore proteins that lack any significant homology to canonical kinetochore components. To date, KKT4 is the only kinetoplastid kinetochore protein that is known to bind microtubules. Here we use X-ray crystallography, NMR spectroscopy, and crosslinking mass spectrometry to characterize the structure and dynamics of KKT4. We show that its microtubule-binding domain consists of a coiled-coil structure followed by a positively charged disordered tail. The structure of the C-terminal BRCT domain of KKT4 reveals that it is likely a phosphorylation-dependent protein-protein interaction domain. The BRCT domain interacts with the N-terminal region of the KKT4 microtubule-binding domain and with a phosphopeptide derived from KKT8. Taken together, these results provide structural insights into the unconventional kinetoplastid kinetochore protein KKT4. Structures of microtubule-binding and BRCT domains in KKT4 are reported The microtubule-binding domain consists of a coiled coil and a disordered tail KKT4 interacts with microtubules via a basic surface at the coiled-coil N terminus KKT4 has a phosphopeptide-binding BRCT domain
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Affiliation(s)
- Patryk Ludzia
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Edward D Lowe
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Gabriele Marcianò
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Shabaz Mohammed
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | | | - Bungo Akiyoshi
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK.
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13
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Ong JY, Bradley MC, Torres JZ. Phospho-regulation of mitotic spindle assembly. Cytoskeleton (Hoboken) 2020; 77:558-578. [PMID: 33280275 PMCID: PMC7898546 DOI: 10.1002/cm.21649] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 10/08/2020] [Accepted: 12/02/2020] [Indexed: 12/23/2022]
Abstract
The assembly of the bipolar mitotic spindle requires the careful orchestration of a myriad of enzyme activities like protein posttranslational modifications. Among these, phosphorylation has arisen as the principle mode for spatially and temporally activating the proteins involved in early mitotic spindle assembly processes. Here, we review key kinases, phosphatases, and phosphorylation events that regulate critical aspects of these processes. We highlight key phosphorylation substrates that are important for ensuring the fidelity of centriole duplication, centrosome maturation, and the establishment of the bipolar spindle. We also highlight techniques used to understand kinase-substrate relationships and to study phosphorylation events. We conclude with perspectives on the field of posttranslational modifications in early mitotic spindle assembly.
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Affiliation(s)
- Joseph Y Ong
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California, USA
| | - Michelle C Bradley
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California, USA
| | - Jorge Z Torres
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California, USA.,Molecular Biology Institute, University of California, Los Angeles, California, USA.,Jonsson Comprehensive Cancer Center, University of California, Los Angeles, California, USA
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14
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Kukreja AA, Kavuri S, Joglekar AP. Microtubule Attachment and Centromeric Tension Shape the Protein Architecture of the Human Kinetochore. Curr Biol 2020; 30:4869-4881.e5. [PMID: 33035484 DOI: 10.1016/j.cub.2020.09.038] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 07/23/2020] [Accepted: 09/14/2020] [Indexed: 12/18/2022]
Abstract
The nanoscale protein architecture of the kinetochore plays an integral role in specifying the mechanisms underlying its functions in chromosome segregation. However, defining this architecture in human cells remains challenging because of the large size and compositional complexity of the kinetochore. Here, we use Förster resonance energy transfer to reveal the architecture of individual kinetochore-microtubule attachments in human cells. We find that the microtubule-binding domains of the Ndc80 complex cluster at the microtubule plus end. This clustering occurs only after microtubule attachment, and it increases proportionally with centromeric tension. Surprisingly, Ndc80 complex clustering is independent of the organization and number of its centromeric receptors. Moreover, this clustering is similar in yeast and human kinetochores despite significant differences in their centromeric organizations. These and other data suggest that the microtubule-binding interface of the human kinetochore behaves like a flexible "lawn" despite being nucleated by repeating biochemical subunits.
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Affiliation(s)
- Alexander A Kukreja
- Department of Biophysics, University of Michigan, 930 N. University Avenue, Ann Arbor, MI 48109, USA
| | - Sisira Kavuri
- Department of Cellular & Developmental Biology, University of Michigan, 109 Zina Pitcher Place, Ann Arbor, MI 48109, USA
| | - Ajit P Joglekar
- Department of Biophysics, University of Michigan, 930 N. University Avenue, Ann Arbor, MI 48109, USA; Department of Cellular & Developmental Biology, University of Michigan, 109 Zina Pitcher Place, Ann Arbor, MI 48109, USA.
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15
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Microtubules pull the strings: disordered sequences as efficient couplers of microtubule-generated force. Essays Biochem 2020; 64:371-382. [PMID: 32502246 DOI: 10.1042/ebc20190078] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 05/01/2020] [Accepted: 05/14/2020] [Indexed: 11/17/2022]
Abstract
Microtubules are dynamic polymers that grow and shrink through addition or loss of tubulin subunits at their ends. Microtubule ends generate mechanical force that moves chromosomes and cellular organelles, and provides mechanical tension. Recent literature describes a number of proteins and protein complexes that couple dynamics of microtubule ends to movements of their cellular cargoes. These 'couplers' are quite diverse in their microtubule-binding domains (MTBDs), while sharing similarity in function, but a systematic understanding of the principles underlying their activity is missing. Here, I review various types of microtubule couplers, focusing on their essential activities: ability to follow microtubule ends and capture microtubule-generated force. Most of the couplers require presence of unstructured positively charged sequences and multivalency in their microtubule-binding sites to efficiently convert the microtubule-generated force into useful connection to a cargo. An overview of the microtubule features supporting end-tracking and force-coupling, and the experimental methods to assess force-coupling properties is also provided.
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16
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Kinetochore-microtubule coupling mechanisms mediated by the Ska1 complex and Cdt1. Essays Biochem 2020; 64:337-347. [PMID: 32844209 DOI: 10.1042/ebc20190075] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 08/03/2020] [Accepted: 08/06/2020] [Indexed: 11/17/2022]
Abstract
The faithful segregation of duplicated sister chromatids rely on the remarkable ability of kinetochores to sustain stable load bearing attachments with the dynamic plus ends of kinetochore-microtubules (kMTs). The outer layer of the kinetochore recruits several motor and non-motor microtubule-associated proteins (MAPs) that help the kinetochores establish and maintain a load bearing dynamic attachment with kMTs. The primary kMT-binding protein, the Ndc80 complex (Ndc80c), which is highly conserved among diverse organisms from yeast to humans, performs this essential function with assistance from other MAPs. These MAPs are not an integral part of the kinetochore, but they localize to the kinetochore periodically throughout mitosis and regulate the strength of the kinetochore microtubule attachments. Here, we attempt to summarize the recent advances that have been made toward furthering our understanding of this co-operation between the Ndc80c and these MAPs, focusing on the spindle and kinetochore-associated 1 (Ska1) complex (Ska1c) and Cdc10-dependent transcript 1 (Cdt1) in humans.
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17
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Zhang Q, Hu L, Chen Y, Tian W, Liu H. Multisite phosphorylation determines the formation of Ska-Ndc80 macro-complexes that are essential for chromosome segregation during mitosis. Mol Biol Cell 2020; 31:1892-1903. [PMID: 32491969 PMCID: PMC7525821 DOI: 10.1091/mbc.e19-10-0569] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The human Ska complex (Ska) localizing to both spindle microtubules and kinetochores is essential for proper chromosome segregation during mitosis. Although several mechanisms have been proposed to explain how Ska is recruited to kinetochores, it is still not fully understood. By analyzing Ska3 phosphorylation, we identified six critical Cdk1 sites, including the previously identified Thr358 and Thr360. Mutations of these sites to phospho-deficient alanine (6A) in cells completely abolished Ska3 localization to kinetochores and Ska functions in chromosome segregation. In vitro, Cdk1 phosphorylation on Ska enhanced WT, not phospho-deficient 6A, binding to Ndc80C. Strikingly, the phosphomimetic Ska 6D complex formed a stable macro-complex with Ndc80C, but Ska WT failed to do so. These results suggest that multisite Cdk1 phosphorylation-enabled Ska–Ndc80 binding is decisive for Ska localization to kinetochores and its functions. Moreover, we found that Ska decrease at kinetochores triggered by the microtubule-depolymerizing drug nocodazole is independent of Aurora B but can be overridden by Ska3 overexpression, suggestive of a role of spindle microtubules in promoting Ska kinetochore recruitment. Thus, based on the current and previous results, we propose that multisite Cdk1 phosphorylation is critical for the formation of Ska–Ndc80 macro-complexes that are essential for chromosome segregation.
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Affiliation(s)
- Qian Zhang
- Department of Biochemistry and Molecular Biology, Tulane University Health Science Center, New Orleans, LA 70112
| | - Liqiao Hu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Yujue Chen
- Department of Biochemistry and Molecular Biology, Tulane University Health Science Center, New Orleans, LA 70112
| | - Wei Tian
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Hong Liu
- Department of Biochemistry and Molecular Biology, Tulane University Health Science Center, New Orleans, LA 70112
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18
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Huis In 't Veld PJ, Volkov VA, Stender ID, Musacchio A, Dogterom M. Molecular determinants of the Ska-Ndc80 interaction and their influence on microtubule tracking and force-coupling. eLife 2019; 8:49539. [PMID: 31804178 PMCID: PMC6927755 DOI: 10.7554/elife.49539] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Accepted: 11/26/2019] [Indexed: 12/12/2022] Open
Abstract
Errorless chromosome segregation requires load-bearing attachments of the plus ends of spindle microtubules to chromosome structures named kinetochores. How these end-on kinetochore attachments are established following initial lateral contacts with the microtubule lattice is poorly understood. Two microtubule-binding complexes, the Ndc80 and Ska complexes, are important for efficient end-on coupling and may function as a unit in this process, but precise conditions for their interaction are unknown. Here, we report that the Ska-Ndc80 interaction is phosphorylation-dependent and does not require microtubules, applied force, or several previously identified functional determinants including the Ndc80-loop and the Ndc80-tail. Both the Ndc80-tail, which we reveal to be essential for microtubule end-tracking, and Ndc80-bound Ska stabilize microtubule ends in a stalled conformation. Modulation of force-coupling efficiency demonstrates that the duration of stalled microtubule disassembly predicts whether a microtubule is stabilized and rescued by the kinetochore, likely reflecting a structural transition of the microtubule end.
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Affiliation(s)
- Pim J Huis In 't Veld
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Vladimir A Volkov
- Department of Bionanoscience, Faculty of Applied Sciences, Delft University of Technology, Delft, Netherlands
| | - Isabelle D Stender
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Andrea Musacchio
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Dortmund, Germany.,Centre for Medical Biotechnology, Faculty of Biology, University Duisburg, Essen, Germany
| | - Marileen Dogterom
- Department of Bionanoscience, Faculty of Applied Sciences, Delft University of Technology, Delft, Netherlands
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19
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Yu W, Min D, Lin F, Zheng S, Tang L, He A, Hu H, Shen Z. SKA1 induces de novo MTX-resistance in osteosarcoma through inhibiting FPGS transcription. FEBS J 2019; 286:2399-2414. [PMID: 30851225 DOI: 10.1111/febs.14808] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 12/22/2018] [Accepted: 03/07/2019] [Indexed: 12/30/2022]
Abstract
De novo methotrexate (MTX)-resistance, whose underlying mechanism remains largely unknown, usually leads to very poor prognosis in patients with osteosarcoma (OS). In this study, we established the de novo MTX-resistant OS cell line SF-86 and identified the candidate gene spindle and kinetochore associated complex subunit 1 (SKA1) as potentially related to de novo MTX-resistance. Analysis of a cohort of 95 OS patients demonstrated that SKA1 overexpression significantly correlated with de novo MTX-resistance and poor 5-year survival. Mechanistically, SKA1 overexpression lead to a downregulation of folylpoly-γ-glutamate synthetase (FPGS), a key enzyme that converts MTX into its active form, MTX-PG. We further demonstrated that SKA1 interacts with DNA-directed RNA polymerase II subunit RPB3. ChIP analysis revealed that RPB3 binds the promoter region of the FPGS gene and triggers FPGS transcription upon MTX treatment in SW1353, a MTX-sensitive OS cell line lacking endogenous SKA1 expression. On the contrary, this process is blocked in SF-86 cells due to the formation of an inhibitory SKA1-RPB3 complex. Furthermore, downregulation of SKA1 levels restores MTX sensitivity in SF-86. Collectively, our study has established the de novo MTX-resistant cell line SF-86 and identified SKA1 as a novel regulator of FPGS, playing a key role in the development of de novo MTX-resistance in OS.
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Affiliation(s)
- Wenxi Yu
- Department of Oncology, Affiliated 6th People's Hospital, Shanghai Jiaotong University, China
| | - Daliu Min
- East Campus, Department of Oncology, Affiliated 6th People's Hospital, Shanghai Jiaotong University, China
| | - Feng Lin
- Department of Oncology, Affiliated 6th People's Hospital, Shanghai Jiaotong University, China
| | - Shuier Zheng
- Department of Oncology, Affiliated 6th People's Hospital, Shanghai Jiaotong University, China
| | - Lina Tang
- Department of Oncology, Affiliated 6th People's Hospital, Shanghai Jiaotong University, China
| | - Aina He
- Department of Oncology, Affiliated 6th People's Hospital, Shanghai Jiaotong University, China
| | - Haiyan Hu
- Department of Oncology, Affiliated 6th People's Hospital, Shanghai Jiaotong University, China
| | - Zan Shen
- Department of Oncology, Affiliated 6th People's Hospital, Shanghai Jiaotong University, China
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20
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Moura M, Conde C. Phosphatases in Mitosis: Roles and Regulation. Biomolecules 2019; 9:E55. [PMID: 30736436 PMCID: PMC6406801 DOI: 10.3390/biom9020055] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 01/31/2019] [Accepted: 02/01/2019] [Indexed: 02/07/2023] Open
Abstract
Mitosis requires extensive rearrangement of cellular architecture and of subcellular structures so that replicated chromosomes can bind correctly to spindle microtubules and segregate towards opposite poles. This process originates two new daughter nuclei with equal genetic content and relies on highly-dynamic and tightly regulated phosphorylation of numerous cell cycle proteins. A burst in protein phosphorylation orchestrated by several conserved kinases occurs as cells go into and progress through mitosis. The opposing dephosphorylation events are catalyzed by a small set of protein phosphatases, whose importance for the accuracy of mitosis is becoming increasingly appreciated. This review will focus on the established and emerging roles of mitotic phosphatases, describe their structural and biochemical properties, and discuss recent advances in understanding the regulation of phosphatase activity and function.
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Affiliation(s)
- Margarida Moura
- IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal.
- i3S-Instituto de Investigação e Inovação em Saúde da Universidade do Porto, 4200-135, Porto, Portugal.
- Programa Doutoral em Biologia Molecular e Celular (MCbiology), Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, 4050-313 Porto, Portugal.
| | - Carlos Conde
- IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal.
- i3S-Instituto de Investigação e Inovação em Saúde da Universidade do Porto, 4200-135, Porto, Portugal.
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21
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Funabiki H. Correcting aberrant kinetochore microtubule attachments: a hidden regulation of Aurora B on microtubules. Curr Opin Cell Biol 2019; 58:34-41. [PMID: 30684807 DOI: 10.1016/j.ceb.2018.12.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Accepted: 12/16/2018] [Indexed: 01/06/2023]
Abstract
For equal chromosome segregation, a pair of kinetochores on each duplicated chromosome must attach to microtubules connecting to opposite poles. The protein kinase Aurora B plays a critical role in destabilizing microtubules attached in a wrong orientation through phosphorylating kinetochore proteins. The mechanism behind this selective destabilization of aberrant attachments remains elusive. While Aurora B is most enriched on the centromere from prophase to metaphase, emerging evidence suggests the importance of Aurora B on microtubules in this process. Here I discuss two hypothetical models that could explain the requirement of Aurora B on microtubules for selective destabilization of aberrant attachments; microtubule-induced substrate masking and treadmill-removal of Aurora B on microtubules proximal to polymerizing ends.
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Affiliation(s)
- Hironori Funabiki
- Laboratory of Chromosome and Cell Biology, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA.
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22
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Saurin AT. Kinase and Phosphatase Cross-Talk at the Kinetochore. Front Cell Dev Biol 2018; 6:62. [PMID: 29971233 PMCID: PMC6018199 DOI: 10.3389/fcell.2018.00062] [Citation(s) in RCA: 87] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 05/31/2018] [Indexed: 01/26/2023] Open
Abstract
Multiple kinases and phosphatases act on the kinetochore to control chromosome segregation: Aurora B, Mps1, Bub1, Plk1, Cdk1, PP1, and PP2A-B56, have all been shown to regulate both kinetochore-microtubule attachments and the spindle assembly checkpoint. Given that so many kinases and phosphatases converge onto two key mitotic processes, it is perhaps not surprising to learn that they are, quite literally, entangled in cross-talk. Inhibition of any one of these enzymes produces secondary effects on all the others, which results in a complicated picture that is very difficult to interpret. This review aims to clarify this picture by first collating the direct effects of each enzyme into one overarching schematic of regulation at the Knl1/Mis12/Ndc80 (KMN) network (a major signaling hub at the outer kinetochore). This schematic will then be used to discuss the implications of the cross-talk that connects these enzymes; both in terms of why it may be needed to produce the right type of kinetochore signals and why it nevertheless complicates our interpretations about which enzymes control what processes. Finally, some general experimental approaches will be discussed that could help to characterize kinetochore signaling by dissociating the direct from indirect effect of kinase or phosphatase inhibition in vivo. Together, this review should provide a framework to help understand how a network of kinases and phosphatases cooperate to regulate two key mitotic processes.
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Affiliation(s)
- Adrian T. Saurin
- Jacqui Wood Cancer Centre, School of Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, United Kingdom
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23
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Zhang Q, Chen Y, Yang L, Liu H. Multitasking Ska in Chromosome Segregation: Its Distinct Pools Might Specify Various Functions. Bioessays 2018; 40. [PMID: 29359816 DOI: 10.1002/bies.201700176] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2017] [Revised: 12/12/2017] [Indexed: 01/31/2023]
Abstract
The human spindle and kinetochore associated (Ska) complex is required for proper mitotic progression. Extensive studies have demonstrated its important functions in both stable kinetochore-microtubule interactions and spindle checkpoint silencing. We suggest a model to explain how various Ska functions might be fulfilled by distinct pools of Ska at kinetochores. The Ndc80-loop pool of Ska is recruited by the Ndc80 loop, or together with some of its flanking sequences, and the recruitment is also dependent on Cdk1-mediated Ska3 phosphorylation. This pool seems to play a more important role in silencing the spindle checkpoint than stabilizing kinetochore-microtubule interactions. In contrast, the Ndc80-N-terminus pool of Ska is recruited by the N-terminal domains of Ndc80 and appears to be more important for stabilizing kinetochore-microtubule interactions. Here, we review and discuss the evidence that supports this model and suggest further experiments to test the functioning mechanisms of the Ska complex.
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Affiliation(s)
- Qian Zhang
- Department of Biochemistry and Molecular Biology and Tulane Center for Aging, Tulane University Health Sciences Center, New Orleans, LA, 70112, USA
| | - Yujue Chen
- Department of Biochemistry and Molecular Biology and Tulane Center for Aging, Tulane University Health Sciences Center, New Orleans, LA, 70112, USA
| | - Lu Yang
- Department of Biochemistry and Molecular Biology and Tulane Center for Aging, Tulane University Health Sciences Center, New Orleans, LA, 70112, USA
| | - Hong Liu
- Department of Biochemistry and Molecular Biology and Tulane Center for Aging, Tulane University Health Sciences Center, New Orleans, LA, 70112, USA
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24
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Monda JK, Whitney IP, Tarasovetc EV, Wilson-Kubalek E, Milligan RA, Grishchuk EL, Cheeseman IM. Microtubule Tip Tracking by the Spindle and Kinetochore Protein Ska1 Requires Diverse Tubulin-Interacting Surfaces. Curr Biol 2017; 27:3666-3675.e6. [PMID: 29153323 DOI: 10.1016/j.cub.2017.10.018] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2017] [Revised: 08/02/2017] [Accepted: 10/05/2017] [Indexed: 12/14/2022]
Abstract
The macromolecular kinetochore functions to generate interactions between chromosomal DNA and spindle microtubules [1]. To facilitate chromosome movement and segregation, kinetochores must maintain associations with both growing and shrinking microtubule ends. It is critical to define the proteins and their properties that allow kinetochores to associate with dynamic microtubules. The kinetochore-localized human Ska1 complex binds to microtubules and tracks with depolymerizing microtubule ends [2]. We now demonstrate that the Ska1 complex also autonomously tracks with growing microtubule ends in vitro, a key property that would allow this complex to act at kinetochores to mediate persistent associations with dynamic microtubules. To define the basis for Ska1 complex interactions with dynamic microtubules, we investigated the tubulin-binding properties of the Ska1 microtubule binding domain. In addition to binding to the microtubule lattice and dolastatin-induced protofilament-like structures, we demonstrate that the Ska1 microtubule binding domain can associate with soluble tubulin heterodimers and promote assembly of oligomeric ring-like tubulin structures. We generated mutations on distinct surfaces of the Ska1 microtubule binding domain that disrupt binding to soluble tubulin but do not prevent microtubule binding. These mutants display compromised microtubule tracking activity in vitro and result in defective chromosome alignment and mitotic progression in cells using a CRISPR/Cas9-based replacement assay. Our work supports a model in which multiple surfaces of Ska1 interact with diverse tubulin substrates to associate with dynamic microtubule polymers and facilitate optimal chromosome segregation.
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Affiliation(s)
- Julie K Monda
- Whitehead Institute for Biomedical Research, 455 Main Street, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Ian P Whitney
- Whitehead Institute for Biomedical Research, 455 Main Street, Cambridge, MA 02142, USA
| | - Ekaterina V Tarasovetc
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Center for Theoretical Problems of Physicochemical Pharmacology, Russian Academy of Sciences, Moscow, Russia
| | | | - Ronald A Milligan
- Department of Cell Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Ekaterina L Grishchuk
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Iain M Cheeseman
- Whitehead Institute for Biomedical Research, 455 Main Street, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA.
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25
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Sivakumar S, Gorbsky GJ. Phosphatase-regulated recruitment of the spindle- and kinetochore-associated (Ska) complex to kinetochores. Biol Open 2017; 6:1672-1679. [PMID: 28982702 PMCID: PMC5703607 DOI: 10.1242/bio.026930] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Kinetochores move chromosomes on dynamic spindle microtubules and regulate signaling of the spindle checkpoint. The spindle- and kinetochore-associated (Ska) complex, a hexamer composed of two copies of Ska1, Ska2 and Ska3, has been implicated in both roles. Phosphorylation of kinetochore components by the well-studied mitotic kinases Cdk1, Aurora B, Plk1, Mps1, and Bub1 regulate chromosome movement and checkpoint signaling. Roles for the opposing phosphatases are more poorly defined. Recently, we showed that the C terminus of Ska1 recruits protein phosphatase 1 (PP1) to kinetochores. Here we show that PP1 and protein phosphatase 2A (PP2A) both promote accumulation of Ska at kinetochores. Depletion of PP1 or PP2A by siRNA reduces Ska binding at kinetochores, impairs alignment of chromosomes to the spindle midplane, and causes metaphase delay or arrest, phenotypes that are also seen after depletion of Ska. Artificial tethering of PP1 to the outer kinetochore protein Nuf2 promotes Ska recruitment to kinetochores, and it reduces but does not fully rescue chromosome alignment and metaphase arrest defects seen after Ska depletion. We propose that Ska has multiple functions in promoting mitotic progression and that kinetochore-associated phosphatases function in a positive feedback cycle to reinforce Ska complex accumulation at kinetochores. Summary: Feedback between protein phosphatases and the spindle- and kinetochore-associated (Ska) complex regulates chromosome movement and the metaphase-to-anaphase cell cycle transition. This article has an associated First Person interview with the first author of the paper as part of the supplementary information.
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Affiliation(s)
- Sushama Sivakumar
- Cell Cycle and Cancer Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
| | - Gary J Gorbsky
- Cell Cycle and Cancer Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
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26
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Kinetochore-microtubule interactions in chromosome segregation: lessons from yeast and mammalian cells. Biochem J 2017; 474:3559-3577. [PMID: 29046344 DOI: 10.1042/bcj20170518] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 08/24/2017] [Accepted: 09/11/2017] [Indexed: 02/06/2023]
Abstract
Chromosome congression and segregation require robust yet dynamic attachment of the kinetochore with the spindle microtubules. Force generated at the kinetochore-microtubule interface plays a vital role to drive the attachment, as it is required to move chromosomes and to provide signal to sense correct attachments. To understand the mechanisms underlying these processes, it is critical to describe how the force is generated and how the molecules at the kinetochore-microtubule interface are organized and assembled to withstand the force and respond to it. Research in the past few years or so has revealed interesting insights into the structural organization and architecture of kinetochore proteins that couple kinetochore attachment to the spindle microtubules. Interestingly, despite diversities in the molecular players and their modes of action, there appears to be architectural similarity of the kinetochore-coupling machines in lower to higher eukaryotes. The present review focuses on the most recent advances in understanding of the molecular and structural aspects of kinetochore-microtubule interaction based on the studies in yeast and vertebrate cells.
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Auckland P, Clarke NI, Royle SJ, McAinsh AD. Congressing kinetochores progressively load Ska complexes to prevent force-dependent detachment. J Cell Biol 2017; 216:1623-1639. [PMID: 28495837 PMCID: PMC5461014 DOI: 10.1083/jcb.201607096] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 12/09/2016] [Accepted: 03/13/2017] [Indexed: 12/19/2022] Open
Abstract
Kinetochores mediate chromosome congression by either sliding along the lattice of spindle microtubules or forming end-on attachments to their depolymerizing plus-ends. By following the fates of individual kinetochores as they congress in live cells, we reveal that the Ska complex is required for a distinct substep of the depolymerization-coupled pulling mechanism. Ska depletion increases the frequency of naturally occurring, force-dependent P kinetochore detachment events, while being dispensable for the initial biorientation and movement of chromosomes. In unperturbed cells, these release events are followed by reattachment and successful congression, whereas in Ska-depleted cells, detached kinetochores remain in a futile reattachment/detachment cycle that prevents congression. We further find that Ska is progressively loaded onto bioriented kinetochore pairs as they congress. We thus propose a model in which kinetochores mature through Ska complex recruitment and that this is required for improved load-bearing capacity and silencing of the spindle assembly checkpoint.
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Affiliation(s)
- Philip Auckland
- Centre for Mechanochemical Cell Biology, Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry CV4 7AL, England, UK
| | - Nicholas I Clarke
- Centre for Mechanochemical Cell Biology, Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry CV4 7AL, England, UK
| | - Stephen J Royle
- Centre for Mechanochemical Cell Biology, Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry CV4 7AL, England, UK
| | - Andrew D McAinsh
- Centre for Mechanochemical Cell Biology, Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry CV4 7AL, England, UK
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Cheerambathur DK, Prevo B, Hattersley N, Lewellyn L, Corbett KD, Oegema K, Desai A. Dephosphorylation of the Ndc80 Tail Stabilizes Kinetochore-Microtubule Attachments via the Ska Complex. Dev Cell 2017; 41:424-437.e4. [PMID: 28535376 PMCID: PMC5572820 DOI: 10.1016/j.devcel.2017.04.013] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 03/16/2017] [Accepted: 04/19/2017] [Indexed: 12/24/2022]
Abstract
During cell division, genome inheritance is orchestrated by microtubule attachments formed at kinetochores of mitotic chromosomes. The primary microtubule coupler at the kinetochore, the Ndc80 complex, is regulated by Aurora kinase phosphorylation of its N-terminal tail. Dephosphorylation is proposed to stabilize kinetochore-microtubule attachments by strengthening electrostatic interactions of the tail with the microtubule lattice. Here, we show that removal of the Ndc80 tail, which compromises in vitro microtubule binding, has no effect on kinetochore-microtubule attachments in the Caenorhabditis elegans embryo. Despite this, preventing Aurora phosphorylation of the tail results in prematurely stable attachments that restrain spindle elongation. This premature stabilization requires the conserved microtubule-binding Ska complex, which enriches at attachment sites prior to anaphase onset to dampen chromosome motion. We propose that Ndc80-tail dephosphorylation promotes stabilization of kinetochore-microtubule attachments via the Ska complex and that this mechanism ensures accurate segregation by constraining chromosome motion following biorientation on the spindle.
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Affiliation(s)
- Dhanya K Cheerambathur
- Ludwig Institute for Cancer Research, CMM-E Room 3052, 9500 Gilman Drive, La Jolla, CA 92093-0653, USA; Department of Cellular & Molecular Medicine, University of California San Diego, La Jolla, CA 92093, USA.
| | - Bram Prevo
- Ludwig Institute for Cancer Research, CMM-E Room 3052, 9500 Gilman Drive, La Jolla, CA 92093-0653, USA; Department of Cellular & Molecular Medicine, University of California San Diego, La Jolla, CA 92093, USA
| | - Neil Hattersley
- Ludwig Institute for Cancer Research, CMM-E Room 3052, 9500 Gilman Drive, La Jolla, CA 92093-0653, USA; Department of Cellular & Molecular Medicine, University of California San Diego, La Jolla, CA 92093, USA
| | - Lindsay Lewellyn
- Department of Biological Sciences, Butler University, 4600 Sunset Boulevard, Indianapolis, IN 46208, USA
| | - Kevin D Corbett
- Ludwig Institute for Cancer Research, CMM-E Room 3052, 9500 Gilman Drive, La Jolla, CA 92093-0653, USA; Department of Cellular & Molecular Medicine, University of California San Diego, La Jolla, CA 92093, USA
| | - Karen Oegema
- Ludwig Institute for Cancer Research, CMM-E Room 3052, 9500 Gilman Drive, La Jolla, CA 92093-0653, USA; Department of Cellular & Molecular Medicine, University of California San Diego, La Jolla, CA 92093, USA
| | - Arshad Desai
- Ludwig Institute for Cancer Research, CMM-E Room 3052, 9500 Gilman Drive, La Jolla, CA 92093-0653, USA; Department of Cellular & Molecular Medicine, University of California San Diego, La Jolla, CA 92093, USA.
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Zhang Q, Sivakumar S, Chen Y, Gao H, Yang L, Yuan Z, Yu H, Liu H. Ska3 Phosphorylated by Cdk1 Binds Ndc80 and Recruits Ska to Kinetochores to Promote Mitotic Progression. Curr Biol 2017; 27:1477-1484.e4. [PMID: 28479321 DOI: 10.1016/j.cub.2017.03.060] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Revised: 02/27/2017] [Accepted: 03/24/2017] [Indexed: 02/05/2023]
Abstract
The spindle and kinetochore-associated (Ska) protein complex is required for accurate chromosome segregation during mitosis [1-6] and consists of two copies each of Ska1, Ska2, and Ska3 proteins [4, 7]. The Ska complex contains multiple microtubule-binding elements and promotes kinetochore-microtubule attachment [8-11]. The Ska1 C-terminal domain (CTD) recruits protein phosphatase 1 (PP1) to kinetochores to promote timely anaphase onset [12]. The Ska complex regulates, and is regulated by, Aurora B [13]. Aurora B phosphorylates both Ska1 and Ska3 to inhibit the kinetochore localization of the Ska complex [14]. Despite its multitude of functions at kinetochores, how the Ska complex itself is recruited to kinetochores is unclear. It is unknown whether any mitotic kinases positively regulate the localization of the Ska complex to kinetochores. Here, we show that Cdk1 phosphorylates Ska3 to promote its direct binding to the Ndc80 complex (Ndc80C), a core outer kinetochore component. We also show that this phosphorylation occurs specifically during mitosis and is required for the kinetochore localization of the Ska complex. Ska3 mutants deficient in Cdk1 phosphorylation are defective in kinetochore localization but retain microtubule localization. These mutants support chromosome alignment but delay anaphase onset. We propose that Ska3 phosphorylated by Cdk1 in mitosis binds to Ndc80C and recruits the Ska complex to kinetochores where Ska1 can bind both PP1 and microtubules to promote anaphase onset.
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Affiliation(s)
- Qian Zhang
- Department of Biochemistry and Molecular Biology, Tulane University Health Science Center, 1430 Tulane Avenue, New Orleans, LA 70112, USA
| | - Sushama Sivakumar
- Howard Hughes Medical Institute, Department of Pharmacology, University of Texas Southwestern Medical Center, 6001 Forest Park Road, Dallas, TX 75390, USA
| | - Yujue Chen
- Department of Biochemistry and Molecular Biology, Tulane University Health Science Center, 1430 Tulane Avenue, New Orleans, LA 70112, USA
| | - Haishan Gao
- Howard Hughes Medical Institute, Department of Pharmacology, University of Texas Southwestern Medical Center, 6001 Forest Park Road, Dallas, TX 75390, USA
| | - Lu Yang
- Department of Biochemistry and Molecular Biology, Tulane University Health Science Center, 1430 Tulane Avenue, New Orleans, LA 70112, USA
| | - Zhu Yuan
- Department of Biochemistry and Molecular Biology, Tulane University Health Science Center, 1430 Tulane Avenue, New Orleans, LA 70112, USA; State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University/Collaborative Innovation Center of Biotherapy, West China Hospital, Sichuan University, 17 People's South Road, Chengdu, Sichuan 610041, China
| | - Hongtao Yu
- Howard Hughes Medical Institute, Department of Pharmacology, University of Texas Southwestern Medical Center, 6001 Forest Park Road, Dallas, TX 75390, USA
| | - Hong Liu
- Department of Biochemistry and Molecular Biology, Tulane University Health Science Center, 1430 Tulane Avenue, New Orleans, LA 70112, USA.
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Musacchio A, Desai A. A Molecular View of Kinetochore Assembly and Function. BIOLOGY 2017; 6:E5. [PMID: 28125021 PMCID: PMC5371998 DOI: 10.3390/biology6010005] [Citation(s) in RCA: 310] [Impact Index Per Article: 44.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 01/16/2017] [Accepted: 01/17/2017] [Indexed: 12/15/2022]
Abstract
Kinetochores are large protein assemblies that connect chromosomes to microtubules of the mitotic and meiotic spindles in order to distribute the replicated genome from a mother cell to its daughters. Kinetochores also control feedback mechanisms responsible for the correction of incorrect microtubule attachments, and for the coordination of chromosome attachment with cell cycle progression. Finally, kinetochores contribute to their own preservation, across generations, at the specific chromosomal loci devoted to host them, the centromeres. They achieve this in most species by exploiting an epigenetic, DNA-sequence-independent mechanism; notable exceptions are budding yeasts where a specific sequence is associated with centromere function. In the last 15 years, extensive progress in the elucidation of the composition of the kinetochore and the identification of various physical and functional modules within its substructure has led to a much deeper molecular understanding of kinetochore organization and the origins of its functional output. Here, we provide a broad summary of this progress, focusing primarily on kinetochores of humans and budding yeast, while highlighting work from other models, and present important unresolved questions for future studies.
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Affiliation(s)
- Andrea Musacchio
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn Straße 11, Dortmund 44227, Germany.
- Centre for Medical Biotechnology, Faculty of Biology, University Duisburg-Essen, Essen 45117, Germany.
| | - Arshad Desai
- Ludwig Institute for Cancer Research, La Jolla, CA 92093, USA.
- Department of Cellular & Molecular Medicine, 9500 Gilman Dr., La Jolla, CA 92093, USA.
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